Impact analysis of transport flasks

This paper presents a methodology, based on the computer programs NOVA2D and NOVA3D, for carrying out the dynamic non-linear analyses required for impact assessment of spent nuclear fuel transport flasks. The procedures implemented are able to treat both geometrical non-linearities (such as contact interfaces, large strains and rotations) and constitutive non-linearities (including non-linear strain hardening and strain-rate dependence). As an example, some analysis of a generic cylindrical flask are undertaken. The 9m drops onto unyielding targets are presented both for a flat-on-end drop (axisymmetric analysis) and for an edge drop (three-dimensional analysis). A 36m edge drop is also studied for comparison. It is concluded that the flat-on-end lid drop is not too far from elastic and leads to high decelerations for the flask internals, while the substantial localised plasticity induced in corner drops has a shock absorbing effect leading to much lower decelerations. (author)